Franklin D. Roosevelt

From Memory Alpha, the free Star Trek reference.

A picture of Roosevelt

FDR as seen through the Guardian of Forever.

Franklin Delano Roosevelt, (also known as 'FDR'), was a 20th century Human who served as the 32nd President of the United States from 1933 until his death in 1945, longer than any president in history.

After Jonathan Archer restored a damaged timeline, Franklin D. Roosevelt giving a speech could be seen in the time stream as the timeline realigned itself. (ENT: "Storm Front, Part II")

In an alternate timeline, Leonard McCoy saved Edith Keeler from a traffic accident, allowing her to continue striving for her goals of peace and eventually founding one of the largest peace movements in the United States. Her actions finally attracted the attention of President Roosevelt, with whom she met on February 23, 1936, to confer on her plan of action for assisting the needy. (TOS: "The City on the Edge of Forever")

In the alternate 1944 presented in ENT: "Storm Front, Part II", Alicia Travers stated the president had called upon the Americans to fight the Nazi invasion of the USA, shortly before he left Washington D.C.. It's possible this unnamed president was Roosevelt too, but since that timeline had been drastically changed as early as 1916, this is only one possibility.

In a holoprogram set in 1944 France, a picture of Roosevelt adorned the tent of Captain Miller. (VOY: "The Killing Game") One also adorned the office of Dixon Hill's secretary, Madeline (TNG: "The Big Goodbye"), and later Dixon Hill's own office. (TNG: "Manhunt")

A headline from a 1941 edition of the San Francisco Herald read "Hitler on the move", followed with the subheading that stated "Roosevelt presses Congress for British aid." (TNG: "The Big Goodbye")

Roosevelt speaking before a crowd during World War II, promoting war bonds, were among the images of Human history on Earth displayed by the Guardian of Forever. (TOS: "The City on the Edge of Forever")